Process and mechanism for connecting electrical conductors



March19, 1929. J, DEMPSYEY 1,705,964

PROCESS AND MECHANISM FOR CONNECTING ELECTRICAL CONDUCTORS' Filed May17, 1926 2 Sheets-Sheet 1 ATTORNEY March 19,' 1929. J. B; DEMPSEY1,705,964

- PROCESS AND MECHNNISM FOR CONNECTING ELECTRICAL CONDUCTORS Filed May17, 1926 2 Sheets-Sheet 2 Fig.5.

Will/I, VIII/4m mam will? INVENTOR (XE/m2; B.Iem,asey.

ATTORN EY Patented Mar. 19, 192.9.

UNITED STATES JAMES BRYAN DEMPSEY, or WASHINGTON, m'smnror or COLUMBIA.

PROCESS AND MECHANISM. FOR CON Application filed May 17,

My invention relates to the art of couplings or connectors used injoining together the ends of. two or more electrical conductors, and itprimarily has for its object to provide a new process for effecting thecoupling of connecters by means of which the process may be carried out.

Generically my new process resides inwinding upon the junction of two ormore electrical conductors, as a core, a cable and maintaining thestrands of the cable undercontinued tension.

The immediate object of the present invention is to provide a connectorfor electrical conductors, that requires no soldering, no taping, nselection of size and a minimum amount of skill, pains and judgment onthe part of the workmen.

The connector comprises revoluble members respectively carried atopposite ends of the cable strands and having provisions by which theymay be revolved on their axes, one with relation to another, thereby totwist or untwist the cable strands around the core (accordingly as themembers are turned inone direction or the reverse) and having pro visionfor holding the members against untwisting movements after the connectershall have been placed and the cable strands twisted around theconductor ends as a core.

In its more specific nature the invention resides in those novelfeatures of construction, combination and arrangement of parts, whichwill be hereinafter fully described, then be specifically pointed out inthe appended claims, reference being had to the accompanying drawings,in which Figure 1 is a vertical longitudinal section of a preferredembodiment of my invention, the parts being positioned as when firstassembled with the cable strands in place.

Figure 2 a view'similar to Figure l'showing the relation. of the partsafter the members have been turned to twist the cable strands and thenturned back to untwist them and cause the cable strands to lie expandedto be joined.

Figure 3 is a view similar to Figures 1 and 2, showing how threeconductor ends may be joined together by the employment of myinvention,'the conductor ends being shown in elevation.

Figure 4 is a cross section on the line 4-4 of Figure 3. 7

ready to receive the ends of the connecters NECTING ELECTRICALCONDUCTORS.

1926. Serial No. 109,676.

Figure 5 is an end elevation of the connector with the parts positionedas shown in Figure 1.

Figure 6 is a view similar to Figure 5 showing the position of theconnector parts when the cable strands have been initially twisted inthe process of manufacturing the device.

Figure 7 is an end elevation of the connecter with the parts positionedas shown in Figure 2.

Figure 8 is a vertical longitudinal section of a modified embodiment ofmy invention, showing the use of a split sleeve that may be constrictedaround the conductor ends.

Figure 9 is longitudinal section of another embodiment of the invention.

F igure 10 is a vertical longitudinal section of a further modificationof my invention.

Figure 11 is a detail perspective view of a portion of the structureshown in Figure 10.

Figures 12, 13 and 14 are detail views here inafter referred to.

In the drawings, in which like numerals of reference indicate like partsin all the fig ures, 1 and 2 represent the two relatively rotatableparts of the connector. These parts have, preferably, their entrant endsor months 3 enlarged for a purpose presently explained.

One of the rotatable members is provided with a socket 4, the entranceto which is o l? frusto-conical form, as at 5, while the other member 1is provided with a frusto-conical portion 6 and a cylindrical portion 7to mate with the respective parts 5 and 4. It is also preferred that theparts 6 and 5, either or both of them, be roughened or milled in or derto increase the frictional coefficient.

Each rotatable member 1. and 2 (in the preferred embodiment of theinvention) is provided with one or more (three bein preferable) recesses8 and slots 9 which are made deep enough to allow the heads 10 of thecable strands or wi res 1.1. to clear the conical mouths of theconuccters.

The strands or wires 11 may be themselves composed of a single strand(Fig. l) or of a plurality of strands twisted together (Fig. 10) as arope, or they may be of woven strand construction (Fig. 9), or thestrands 11 may be composed of chains or chain mesh (Fig. 8) thepreferable requirement being that they should be flexible to a degreepermitting twisting and. untwisting. for a reasonable number ofoperations without breaking the strands.

12 designates the wires or conductors to be connected. These conductorsmay be joined lengthwise or they may be entered from the same end of theconnecter or a part entered at one end and the remainder at the otherend, the non-insulated ends of the conductor, however, lying side byside within the connector as shown.

The conductors have the usual insulated covers 13 which when the endsare to be connected, are tapered off toward the exposed ends of theconductor as shown in Figure 3.

In Figure 8 I have illustrated a modified embodiment oi the invent-ion.In this tigure the rotatable men'lbers 1st have conical seats 15 toreceive a split double coned sleeve 16 that is adapted to be contract-edaround the conductor ends oi? the wound cable as the members Lil; aredrawn together when turned to put the cable strands under tension.

In Figure 9 is shown another embodiment of the invcntimi where one oithe connector members 17 is closed at one end. In this (anbodiincnt ofthe invention the connectors to he joined are allcntcredtogether. Inorder to place the cable strands in the member 17 it may bedrilled at 18with a countersunk aperture and afterwards plugged as at 19 to :insureproper insulation.

In Figure 12 I have shown a threaded metal bushing 20 molded into themember L which is adapted to carry a set "screw 21 to assist in holdingthe members 1 and 2 against reverse or untwisting rotation. Instead ofen'lployingz a set screw to]: the purpose as shown in Figure 12, theparts may be drilled after the connector has been applied, and a pin 22inserted as indicated in Figure 13, or if desired the parts maybesecured by soldcring, and in iliigure lat l have indicated one way inwhich this may be done. By reference to Figure 1 it will be observed.that the male element of the member 1 is molded with a. metallic ring,23 having indentations 24:. and the i'i iember 2 may be provided with acountersunk aperture containing a metallic sleeve 25 into which solder26 may be pomicd to unite the rin and duct 25, atter which an insulatingplug 27 may be inserted to close the opening "for insulation purposes.

Vith the partsl and E2 assembled as illus trated and the cable strandsinserted. relative rotation of the parts 1 and .2 twists these wiresinto a cable. Continued rotation twists the cable strands taut so thatwhen untwisted the wires tend to retain the imparted helical.configuration and hug the walls of the bore, leaving maximum room insidefor inserting the conductor ends. It is contemplated that the process ofmanufacture shall include this initial twisting and un'twis tages beingthat the helical formed wires tend ring; the advanto hold themselves inplace and the worlnnan furnished with the article ready to use.

The recesses 8 and slots 9 are made deep enough to allow the heads 10 ofthe cable strands or wires 11 to clear the conical mouths at? theconnectors. The mouths are enlarged to admit a short length otiisulation on the conductors (see Figure 3) as not to leave exposed anybare metal. The mat inn; surfaces land 7 insure coaxial rotation of themolded parts.

The conductor ends are inser d in the connector in any desired relation1 ip; abutting. overlapping, grouped or twisted to; 1'ether; and in anynumber that will enter within the untwisted cable.

IVhen the conductors are inserted. rotating the parts 1 and 2 inopposite directions twists the cable on. the comluctors. as a coreexerting thereon (ZOUFlJl'lClliifl force. it the same time, the pitch otthe cable strands being large. a longitudinal i'orce draws the parts 1and togethe and jams them on the tapered surt aces 5 and (3. Thisjamming prevents bark-slip oi the parts l and 2 and retains the cablestrands taut. It appropriate to mill the surfaces 5 and 6 in themolding; process, so that meshing oi the ridges and valleys assists theamming to prevent loosening.

An ad vantage results in using only three strands tor the cable. It thewires are not equal in length the axis of the cable wound is on" thecenter line of the connector in the direction of the shorter strands.This assures that the load is equally distriluited among; the threestrands. It is olwious that one strand alone would function to make aconnection or that more than three strands may be used it desired.

In Figures 10 and ll is illustrated another modification of my inventionand by rel'i-rcure to these lic urcs it will be seen that th relativclrotatable parts ol the conn ctor consists oit end members 3.8 hav iuitapcrtul or conical surfaces 31 that are adapted to eui 'a 'e thesimilar surfaces 32 oi a tubular intern'iediate member 30, the cablestra ns: if) being secured to the end members 25' in any desirtalfashion.

Thepreparation ot this connector I or by perlimiuarily twisting thestrands i2!) and then untwistinn' them is combo-tell on ilusameprinciple as the other emhodiuwots at my invention, and the manner otusingthi en'lhodii'nci'itis also essen ially the sam and a furtherdetailed description of the embodiment shown in Figures 10 and 11thought to be unnecessary.

Vhile continual twisting: and uutwisting of the connector wouldultinnitel breal: the strands. nevertheless it they are made oi chainsor chain mesh or of woven sulrsiramfls so as to be soi-newhat tlexi'ile. the connccter could be used an indetiaite number eat times usetit)

lit)

for temporary joints without breaking. Furthermore the strands may becomposed of copper plated ierroanetallic wires.

From the foregoing it is to be observed that my invention possesses thefollowing advantages (a) The cable adjusts itself to any conductors orgroup of conductors that will enter the bore.

(b) A steel cable furnishes a great factor oi safety against yield orbreaking.

(c) Qesiding stretch in the wires takes up any yield in the conductorsdeveloped with time.

(d) The grip is eflective throughout the length of the connecter, incontrast to a tapered helixor the set-screw connector.

(6) The character of every joint is unit'orm and does not require anyskill, judgment or much care on the part of the workman.

t No solder, tape or selection of size required; simply insert theconductors and twist until tight. V

(g) The simplicity of application assures that every connection madewith this connector ispractically under the,control oi the UnderwritersLaboratories through their system oil factory inspection. The onlydependence on the workman is that he twist the connecter tight. He isnot depended upon to select a certain size connector, to in sulate theoint with tape nor is he induced to slight the connection as where he isrequired to hold a small device in one hand and bear down on a set screwwith a screw driver: a slip resulting in an injured hand.

(It) This connector is particularly suited to connecting flexible cordswhose strands when spread are interlaced among the con-- necter strandsas the connector is tightened.

From the il oregoing description, taken in connection will theaccompanying drawings, it is thought that my invention will be clear tothose skilled in the art, and it is obvious that slight changes in thedetails of construction of the connecter may readily be made withoutdeparting from the spirit of the invention.

\Vhat I claim is:

l. The method of joining conductors which consists in laying the iductorends together. holding table ads by their respective ends and twin paround the conductors as a core while continually applying force to thecable in a direction along the axis of the core, thereby to keep thecable strands under continual'tension.

2. A connecter comprising two members having central bores, at least oneflexible member positioned within the bore and joining said members,said members having frictional engaging surfaces adapted, when said Ingthe strands members have been turned for the purpose of twisting saidflexible member around the conductors to be joined, as a core, to retaina continual tension in said flexible member.

3. A connector comprising two members oi molded insulation of externalshape to engage a tool, said members having continuous centralcylindrical bores and having surtaces mated for a tapered telescopicengagement for initial coaxial centralization of the members and forfinal mutual jamming as one member is rotated with respect to the other,a plurality of cable strands positioned within the'bores, means forsecuring the ends 0t said strands to the respective members, all beingarranged whereby when said members are turned with relation to oneanother the cable strands will be wound into a cable and the memberswill be drawn together into jamming engagement.

l. A connect-er comprising two members of insulating material havingmating surfaces and rtral bores, said members having flared n'iouthsprovided with T slot-s, cable strands located wi hin said members andhaving their respective ends anchored in the said T slots.

5. A connecter comprising two members having central bores, at least onecable strand located within said members and anchored at its ends to therespective members, said 1 members adapted to be turned on their commonaxis to twist said strand as a helix around inserted conductors, andmeans for maintaining said two members against reverse rotation aftersaid strand has been twisted around inserted conductors.

6. A connecter comprising two members having mating surfaces and centralbores, cable strands located within the bores and having their endsanchored to the respective members, whereby when said members are turnedon their-axes inopposite directions said strands will be wound aroundinserted conductors as a core and said members will be drawn tightlytogether, and means for maintaining said members in their tightenedrelation.

7. A connector comprising members having central bores, cableistrandslocated within said members and having their ends anchored tothe (nitcrmost members, said members including a central. split sleeve,said sleeve and said end members having cngaging surfaces whereby assaid end members are turned to twist said strands around in sortedconductors as a core the end members will be drawn toward one anotherand caused to compress the sleeve.

8. A connector comprising two members having central bores, at least oneflexible member positioned within the bores and having its ends anchoredto the respective members, said two members having engaging surfaces andbeing adapted to be turned 011 a common central axis to twist saiilflexible member arouncl inserted conductors as a core.

9. A eonneeter comprising two members at least one out which has acentral. here, said members telescoping one within the other and capableof rotary motion with respect to each other, at least one flexiblemember positioned within said bore and having its respective enilsfastei'ietl to the respective members whereby upon rotation of said twomembers with respect to each other Silitl flexible member will betwisted around. the electrical conductors which are inserted within thecentral bore substantially as shown anal (lescribed.

10. A connector comprising two sleeve members whose ends are connectedwithin the 3ores by a plurality of flexible strands, which strands aretwisted to give a clamping action upon the electrical conductors whichare inserted within the sleeve members, Sfllil sleeve memberstelescoping one within the other anil being capable oi? rotary motionwith respect to each other substantially as; shown and (leeeribecl.

JAMES BRYAN DEMPSEY.

